Power-on reset circuitry is typically employed as an adjunct to other circuits, such as memories and processors. In principle, power-on reset circuitry operates to provide a repeatable starting point for larger circuit operations as power is applied and the circuit receiving an indication from the power-on reset circuit moves from an un-powered state to a fully-powered state. Typically, the power-on reset circuit indicates to the receiving circuit (e.g., a memory programming circuit) that the power supply voltage has risen, to a level sufficient to conduct normal operations.
Some power-on reset circuits employ positive feedback. Such circuit implementations may use multiple, stacked diodes to set the triggering voltage high enough for their particular application. This design can suffer from trapped charge among the diodes, preventing the complete turn-off of other components in the reset circuit. Receiving circuit operation may be less reliable as a result.